Twin Forks Chapter NRHS
Preserving Railroad History Since 1996.
Position Light Signals on Long Island
Signals at Farm 1 before they were taken down and replaced
The Long Island Rail Road was once a subsidiary of the Pennsylvania Railroad. As such, the LIRR used the Pennsylvania Railroads Position Light Signal System. Although there were slight changes over the years between the LIRR and big brother, The PRR, they were basically the same system.
In the early 2000’s, the LIRR has begun using the Safetran color light signal system that is in operation along with the legacy Position light signals. The two systems are both currently working side by side or more accurately put, it depends on what section of the railroad you are on, determines what system is being used on that particular stretch of railroad.
A position light signal is one where the position of the lights, rather than their color, determines the meaning of the aspect that's being conveyed to the Engineer or other designated employee leading the move. The aspect consists solely of a pattern of illuminated lights, which are all of the same color (typically amber or white). In many countries, small position light signals are used as shunting signals, while the main signals are of color light form.
On the Long Island Rail Road as on other railroads, initial efforts were made to replace the semaphore signal's with the illumination of the position of the blade rather than by color lamps alone. This had the advantage of eliminating any and all effects of even slight color blindness by the train crew. (The PRR realized that 1 in 3 engineers were color blind). Lamps with inverted half toric optic lenses, covered with a light yellow tinted conical cover glass with a frosted tip to avoid phantom indications were displayed in rows of three, corresponding to the positions of a semaphore blade. Multiple signal heads were used at interlockings where four aspects did not suffice. The Pennsylvania Railroad chose to use their Superintendent of Signaling, A.H.Rudd's, in-house developed position light signals to both replace the semaphores and their moving parts, also because the intense lemon yellow light provided superior visibility in adverse weather conditions such as rain, fog or snow. The prototype position lights used rows of four lamps in an asymmetric fashion in the style of semaphore blades, but this was later changed to the symmetric three-lamp system. The first installation of the four 5 volt 10 watt lamp position light signals occurred on the Mainline between Philadelphia and Paoli, in conjunction with the 1915 electrification. These first signals differed from the later ones in that the lamps were mounted separately in front of a tombstone-shaped black painted metal backing. There were found issues with wind damage due to the rather larger "sail area" of the "tombstone backing." Soon thereafter, the lamps were reduced in number to three per row, without adversely affecting the long range viewing of the signal aspects and the backing correspondingly reduced in size and made as a disc. The lamp units and background disc on a mounting system known as a "spider," were integrated into a single unit.
Below, you will see a chart of position light signals, with an accompanying rule number.
This is an over view of the LIRR/PRR system.
We will take each individual Position Aspect and describe what it means.
Note: On the LIRR the "Dwarf" signals are referred to as "Low-Homes", These are only found in interlockings.
The "Dwarf Pedestal" is referred to simply as "Pedestal(s)"
In simplest terms, a "home signal" is an interlocking signal or
non-interlocked signal which displays "STOP SIGNAL" (Rule 292) as its most restrictive aspect
In the Chart below, the Position Signal is on the Left and the same aspect shown as a Dwarf Signal is to the Right of the position signal.
Proceed: Manual Block Clear (MBS only)
Proceed approaching next signal at medium speed. Note: Trains may proceed approaching next signal at not exceeding 45 miles per hour at signals displaying a yellow triangle outlined in black
Proceed; Medium Speed through interlocking limits.
Trains may at not exceeding 30 MPH within interlocking limits.
In cab signal territory with/without fixed automatic block signals, trains with cab signals in operative condition may proceed not exceeding 40 MPH
Rule 283 A
Proceed at Medium Speed prepared to stop at next signal. Train exceeding Medium speed must begin reduction to medium speed as soon as the medium approach signal is clearly visible
Proceed approaching next signal at slow speed. Train exceeding Medium speed must at once reduce to that speed.
Proceed prepared to stop at next signal. Train exceeding Medium speed must at once reduce to that speed.
Rule 285 A
Train exceeding Medium speed must at once reduce to that speed. Where a facing switch is connected with the signal, approach that switch prepared to stop. Approach next signal prepared to stop. (MBS only)
Proceed; Slow speed within interlocking limits.
Rule – 289
Block occupied; for passenger trains, stop; for trains other than passenger trains, proceed prepared to stop short of train or obstruction, but not exceeding 15 miles per hour
Proceed at Restricted speed
Stop, and then proceed at restricted speed.
NOTE - Freight trains of 90 or more cars or having tonnage of 80 per cent or more of the prescribed engine rating may proceed at Restricted speed without stopping at signals displaying a yellow disc on which is shown the letter "G" in black.
The engineer must be notified as to tonnage and number of cars in train before leaving terminals and when consist is changed enroute.
NOTE: With a Red Flashing Light
Next to the signal aspect.
(Not Pictured here)
Signal rules and aspects make use of several pre-defined speeds. LIRR/PRR used a system of speed signaling which means the signal indicates at least 2 pieces of information to the operator. The aspect indicates the conditions of the block or block ahead, as well as the speed to do while passing that signal and the speed to be at when approaching the next signal ahead.
The following speeds are also used in Route type signaling:
Normal Speed (MAS) - The normal speed for the railroad line, also known as Maximum Authorized Speed.
Limited Speed - A speed less than Normal Speed that was employed starting in the 1940's for use with higher speed switches. This speed is defined by individual railroads and ranges anywhere from 40 miles per hour, to 60 miles per hour.
Medium Speed - Original concept for a standard "reduced" speed normally set to 30 miles per hour. This is the typical speed for diverging movements through interlockings and is also the speed trains are limited to when approaching a Stop or Restricted Proceed-type signals.
Slow Speed - 15 miles per hour while with in the limits of a interlocking and 20mph when not in the limits of a interlocking. This is used for trains negotiating complex trackwork at interlockings.
Restricted Speed - Used for trains entering or operating in unsignaled territory or when entering an de-energized track circuit. Regulatory definition of no greater than 20 miles per hour, outside interlocking limits, 15 mph within interlocking limits. Trains operating at restricted speed must be able to stop within half vision short of any obstruction, and must look out for broken rails.
Signal showing STOP to an eastbound train, as the 153 moves westbound at Mastic-Shirley Photo by R. Gorddard
Long Island Railroad Manual Block Signals
Westbound train at Mattituck, NY. Note the old style Block Signals.
Collection of R. Gorddard
The LIRR Also uses Manual Block Signals.
These signals are used in their ever diminishing Dark Territory”. This means there is no "in" cab signals, The Block signal alone governs the use of the block. Depending on the signal rules in effect on that portion of the railroad it will determine weather the manual block signal alone will authorize train movement or all train movement is governed by train orders with respect to the timetable authority and superiority of trains.
Manual block signal aspects:
Clear Block – Dispatcher authorizes the train to proceed from one block to another as if a clear Block signal was displayed.
Permissive Block- This allows one train to follow another, but the dispatcher keeps a distance between trains.
Stop Signal - Stop and stay
Caution - Used on a distant signal, governing the approach to a home signal if there is a train ahead in the block (permissive block) or if a switch connected to the signal is lined against the main track.
Controlled Manual Block:
A Portion of the railroad in which the manually controlled block is protected by home signals which may or may not be part of an interlocking that protects the block and are so connected to not allow both to display passing aspects at the same time.
These signals supersede the authority of the timetable and the superiority of trains. Trains will be governed by the aspect displayed on the signal in accordance with the rules. LIRR has this in Two locations at the time of this writing. In this territory you will see the Position Light signals and no block limit signals
Single Track Manual Block Signal system territory:
In This territory, Train movement is governed directly by the authority of the timetable, through the superiority of trains and by train orders. It is only here where you will find the Block-Limit signals. These signals do not change aspects, They simply indicate the limit of the block. The main track side of the block-limit signal is yellow and the other side is red in both directions. This signal can be placed on either side of the main track.
Authority for a train or on track equipment to pass is provided on a Clearance card form K, A, C or Train Order as specified by the rules.
This is as basic as it gets on the LIRR and remains in service between Ronkonkoma and Greenport only.
The last run between Speonk and Montauk under this operation was on a very cold November night in 2017
Amtrak Train Heading for the Tunnel to Penn Station, passing Position Signals.
Photo by Richard Gorddard